13 13 /θɜrˈtin/

adjective

1. () Being one more than twelve  ( xiii , thirteen , 13 )
   being one more than twelve
     She celebrated becoming a teenager when she turned thirteen.
   She celebrated becoming a teenager when she turned thirteen.
   

noun

1. The cardinal number that is the sum of twelve and one  ( 13 , baker's dozen , long dozen , thirteen , XIII )
   the cardinal number that is the sum of twelve and one
    My nephew just turned thirteen years old
   My nephew just turned thirteen years old